The name 'Odovacar' is Gothic: in fact, historically, Odovacar was the barbarian who finally overthrew the western Roman Empire. The Hobbits lived millennia before the Goths existed, of course, so Odovacar cannot have been a real Hobbit name. Instead, it merely represents the original, unknown, name for this member of the Bolger family, whose real name would presumably have come from some appropriately famous barbarian of his own history.